Radiant burners are known and are typically used for treating an effluent gas stream from a manufacturing process tool used in, for example, the semiconductor or flat panel display manufacturing industry. During such manufacturing, residual perfluorinated compounds (PFCs) and other compounds exist in the effluent gas stream pumped from the process tool. PFCs are difficult to remove from the effluent gas and their release into the environment is undesirable because they are known to have relatively high greenhouse activity compared to carbon dioxide.
It will be appreciated that various semiconductor or flat panel display manufacturing no processes are utilised. For example, processes such as chemical vapour deposition, epitaxial processes and etching processes may be used and each will have an associated effluent gas stream. Various radiant burners are provided for treatment of those effluent gas streams. It will be appreciated that an appropriate gas burner may be chosen in dependence upon requirements of manufacturing processes.
For example, in the case of chemical vapour deposition manufacturing techniques, a simple radiant burner may be used, whereas a radiant burner used to process effluent gases from epitaxial manufacturing processes may comprise a high flow hydrogen burner, and a suitable radiant burner for processing effluent gases produced by etching processes may comprise a radiant burner and a high-intensity flame provided at the end of a nozzle which introduces effluent into a combustion chamber.
Known radiant burners use combustion to remove the PFCs and other compounds from the effluent gas stream. Such radiant burners typically comprise, a combustion chamber laterally surrounded by an exit surface of a foraminous gas burner. Fuel gas and air are simultaneously supplied to the foraminous burner to effect flameless combustion at the exit surface, with the amount of air passing through the foraminous burner being selected, depending upon application, to be sufficient to consume the fuel gas supplied to the burner, and also as required, any combustibles which may be injected into the combustion chamber.
Effluent gas is introduced into the combustion chamber and, depending on application, the conditions within the combustion chamber may be such that hot gases resulting front the combustion processes may act on the effluent gas and react to form a species which are safe or can be removed via wet scrubbing. Typically, the effluent gas stream is a nitrogen stream in containing PFCs.
As the surface areas of the semiconductors being produced increases, the flow rate of the effluent gas also increases.
Although techniques exist for processing the effluent gas stream, they each have their own shortcomings. Accordingly, it is desired to provide an improved technique for monitoring and controlling operation of a radiant burner.